sha1sum_blob(&tail, &h2);
  rc = blob_compare(pHash, &h2);
  blob_reset(&h2);
  blob_reset(&tail);
  return rc==0;
}


/*
** Check the signature on an application/x-fossil payload received by
** the HTTP server.  The signature is a line of the following form:
**
**        login LOGIN NONCE SIGNATURE
**
** The NONCE is the SHA1 hash of the remainder of the input.  

     "SELECT pw, cap, uid FROM user"
     " WHERE login=%Q"
     "   AND login NOT IN ('anonymous','nobody','developer','reader')"
     "   AND length(pw)>0",
     zLogin
  );
  if( db_step(&q)==SQLITE_ROW ){
    int szPw;
    Blob pw, combined, hash;
    blob_zero(&pw);
    db_ephemeral_blob(&q, 0, &pw);
    szPw = blob_size(&pw);
    blob_zero(&combined);
    blob_copy(&combined, pNonce);
    blob_append(&combined, blob_buffer(&pw), szPw);

    sha1sum_blob(&combined, &hash);
    assert( blob_size(&hash)==40 );
    rc = blob_compare(&hash, pSig);
    blob_reset(&hash);
    blob_reset(&combined);
    if( rc!=0 && szPw!=40 ){
      /* If this server stores cleartext passwords and the password did not
      ** match, then perhaps the client is sending SHA1 passwords.  Try
      ** again with the SHA1 password.
      */
      const char *zPw = db_column_text(&q, 0);
      char *zSecret = sha1_shared_secret(zPw, blob_str(pLogin));
      blob_zero(&combined);
      blob_copy(&combined, pNonce);
      blob_append(&combined, zSecret, -1);
      free(zSecret);
      sha1sum_blob(&combined, &hash);
      rc = blob_compare(&hash, pSig);
      blob_reset(&hash);
      blob_reset(&combined);
    }
    if( rc==0 ){
      const char *zCap;
      zCap = db_column_text(&q, 1);
      login_set_capabilities(zCap);
      g.userUid = db_column_int(&q, 2);
      g.zLogin = mprintf("%b", pLogin);
      g.zNonce = mprintf("%b", pNonce);
      if( g.fHttpTrace ){
        fprintf(stderr, "# login [%s] with capabilities [%s]\n", g.zLogin,zCap);
      }
    }
  }
  db_finalize(&q);

  if( rc==0 ){
    /* If the login was successful. */
    login_set_anon_nobody_capabilities();

    }else
  
    
    /*    pull  SERVERCODE  PROJECTCODE
    **    push  SERVERCODE  PROJECTCODE
    **
    ** The client wants either send or receive.  The server should
    ** verify that the project code matches.

    */
    if( xfer.nToken==3
     && (blob_eq(&xfer.aToken[0], "pull") || blob_eq(&xfer.aToken[0], "push"))
     && blob_is_uuid(&xfer.aToken[1])
     && blob_is_uuid(&xfer.aToken[2])
    ){
      const char *zPCode;






















      zPCode = db_get("project-code", 0);
      if( zPCode==0 ){
        fossil_panic("missing project code");
      }
      if( !blob_eq_str(&xfer.aToken[2], zPCode, -1) ){
        cgi_reset_content();
        @ error wrong\sproject

    **
    ** The client knows nothing.  Tell all.
    */
    if( blob_eq(&xfer.aToken[0], "clone") ){
      login_check_credentials();
      if( !g.okClone ){
        cgi_reset_content();
        @ push %s(db_get("server-code", "x")) %s(db_get("project-code", "x"))
        @ error not\sauthorized\sto\sclone
        nErr++;
        break;
      }
      isClone = 1;
      isPull = 1;
      deltaFlag = 1;

  int pushFlag,           /* True to do a push (or a sync) */
  int pullFlag,           /* True to do a pull (or a sync) */
  int cloneFlag,          /* True if this is a clone */
  int configRcvMask,      /* Receive these configuration items */
  int configSendMask      /* Send these configuration items */
){
  int go = 1;             /* Loop until zero */
  int nCardSent = 0;      /* Number of cards sent */
  int nCardRcvd = 0;      /* Number of cards received */
  int nCycle = 0;         /* Number of round trips to the server */
  int size;               /* Size of a config value */
  int nFileSend = 0;
  int origConfigRcvMask;  /* Original value of configRcvMask */
  int nFileRecv;          /* Number of files received */
  int mxPhantomReq = 200; /* Max number of phantoms to request per comm */
  const char *zCookie;    /* Server cookie */

    "CREATE TEMP TABLE onremote(rid INTEGER PRIMARY KEY);"
  );
  blobarray_zero(xfer.aToken, count(xfer.aToken));
  blob_zero(&send);
  blob_zero(&recv);
  blob_zero(&xfer.err);
  blob_zero(&xfer.line);
  origConfigRcvMask = 0;

  /*
  ** Always begin with a clone, pull, or push message
  */
  if( cloneFlag ){
    blob_appendf(&send, "clone\n");
    pushFlag = 0;
    pullFlag = 0;
    nCardSent++;
    /* TBD: Request all transferable configuration values */
  }else if( pullFlag ){
    blob_appendf(&send, "pull %s %s\n", zSCode, zPCode);
    nCardSent++;
  }
  if( pushFlag ){
    blob_appendf(&send, "push %s %s\n", zSCode, zPCode);
    nCardSent++;
  }
  manifest_crosslink_begin();
  printf(zLabelFormat, "", "Bytes", "Cards", "Artifacts", "Deltas");

  while( go ){
    int newPhantom = 0;
    char *zRandomness;

    ** for all leaves.
    */
    if( pullFlag || cloneFlag ){
      request_phantoms(&xfer, mxPhantomReq);
    }
    if( pushFlag ){
      send_unsent(&xfer);
      nCardSent += send_unclustered(&xfer);
    }

    /* Send configuration parameter requests.  On a clone, delay sending
    ** this until the second cycle since the login card might fail on 
    ** the first cycle.
    */
    if( configRcvMask && (cloneFlag==0 || nCycle>0) ){
      const char *zName;
      zName = configure_first_name(configRcvMask);
      while( zName ){
        blob_appendf(&send, "reqconfig %s\n", zName);
        zName = configure_next_name(configRcvMask);
        nCardSent++;
      }
      if( configRcvMask & (CONFIGSET_USER|CONFIGSET_TKT) ){
        configure_prepare_to_receive(0);
      }
      origConfigRcvMask = configRcvMask;
      configRcvMask = 0;
    }

    /* Send configuration parameters being pushed */
    if( configSendMask ){
      const char *zName;
      zName = configure_first_name(configSendMask);
      while( zName ){
        send_config_card(&xfer, zName);
        zName = configure_next_name(configSendMask);
        nCardSent++;
      }
      configSendMask = 0;
    }

    /* Append randomness to the end of the message.  This makes all
    ** messages unique so that that the login-card nonce will always
    ** be unique.
    */
    zRandomness = db_text(0, "SELECT hex(randomblob(20))");
    blob_appendf(&send, "# %s\n", zRandomness);
    free(zRandomness);

    /* Exchange messages with the server */
    nFileSend = xfer.nFileSent + xfer.nDeltaSent;
    printf(zValueFormat, "Send:",
            blob_size(&send), nCardSent+xfer.nGimmeSent+xfer.nIGotSent,
            xfer.nFileSent, xfer.nDeltaSent);
    nCardSent = 0;
    nCardRcvd = 0;
    xfer.nFileSent = 0;
    xfer.nDeltaSent = 0;
    xfer.nGimmeSent = 0;
    fflush(stdout);
    http_exchange(&send, &recv);
    blob_reset(&send);

    /* Begin constructing the next message (which might never be
    ** sent) by beginning with the pull or push cards
    */
    if( pullFlag ){
      blob_appendf(&send, "pull %s %s\n", zSCode, zPCode);
      nCardSent++;
    }
    if( pushFlag ){
      blob_appendf(&send, "push %s %s\n", zSCode, zPCode);
      nCardSent++;
    }

    /* Process the reply that came back from the server */
    while( blob_line(&recv, &xfer.line) ){
      if( blob_buffer(&xfer.line)[0]=='#' ){
        continue;
      }
      xfer.nToken = blob_tokenize(&xfer.line, xfer.aToken, count(xfer.aToken));
      nCardRcvd++;
      if (!g.fQuiet) {
        printf("\r%d", nCardRcvd);
        fflush(stdout);
      }

      /*   file UUID SIZE \n CONTENT
      **   file UUID DELTASRC SIZE \n CONTENT
      **
      ** Receive a file transmitted from the server.
      */
      if( blob_eq(&xfer.aToken[0],"file") ){

          fossil_fatal("server loop");
        }
        if( zPCode==0 ){
          zPCode = mprintf("%b", &xfer.aToken[2]);
          db_set("project-code", zPCode, 0);
        }
        blob_appendf(&send, "clone\n");
        nCardSent++;
      }else
      
      /*   config NAME SIZE \n CONTENT
      **
      ** Receive a configuration value from the server.
      */
      if( blob_eq(&xfer.aToken[0],"config") && xfer.nToken==3

            ** server.  But this can only happen if we have specifically
            ** requested configuration information from the server, so
            ** presumably the operator trusts the server.
            */
            db_multi_exec("%s", blob_str(&content));
          }
        }
        nCardSent++;
        blob_reset(&content);
        blob_seek(xfer.pIn, 1, BLOB_SEEK_CUR);
      }else

      
      /*    cookie TEXT
      **

      /*   message MESSAGE
      **
      ** Print a message.  Similar to "error" but does not stop processing
      */        
      if( blob_eq(&xfer.aToken[0],"message") && xfer.nToken==2 ){
        char *zMsg = blob_terminate(&xfer.aToken[1]);
        defossilize(zMsg);
        printf("\rServer says: %s\n", zMsg);
      }else

      /*   error MESSAGE
      **
      ** Report an error and abandon the sync session.
      **
      ** Except, when cloning we will sometimes get an error on the
      ** first message exchange because the project-code is unknown
      ** and so the login card on the request was invalid.  The project-code
      ** is returned in the reply before the error card, so second and 
      ** subsequent messages should be OK.  Nevertheless, we need to ignore
      ** the error card on the first message of a clone.
      */        
      if( blob_eq(&xfer.aToken[0],"error") && xfer.nToken==2 ){
        if( !cloneFlag || nCycle>0 ){
          char *zMsg = blob_terminate(&xfer.aToken[1]);
          defossilize(zMsg);
          blob_appendf(&xfer.err, "server says: %s", zMsg);
          printf("Server Error: %s\n", zMsg);
        }
      }else

      /* Unknown message */
      {
        if( blob_str(&xfer.aToken[0])[0]=='<' ){
          fossil_fatal(
            "server replies with HTML instead of fossil sync protocol:\n%b",

      blobarray_reset(xfer.aToken, xfer.nToken);
      blob_reset(&xfer.line);
    }
    if( origConfigRcvMask & (CONFIGSET_TKT|CONFIGSET_USER) ){
      configure_finalize_receive();
    }
    origConfigRcvMask = 0;
    if( nCardRcvd>0 ){
      printf(zValueFormat, "Received:",
              blob_size(&recv), nCardRcvd,
              xfer.nFileRcvd, xfer.nDeltaRcvd + xfer.nDanglingFile);
    }
    blob_reset(&recv);
    nCycle++;
    go = 0;

    /* If we received one or more files on the previous exchange but
    ** there are still phantoms, then go another round.
    */
    nFileRecv = xfer.nFileRcvd + xfer.nDeltaRcvd + xfer.nDanglingFile;
    if( (nFileRecv>0 || newPhantom) && db_exists("SELECT 1 FROM phantom") ){
      go = 1;
      mxPhantomReq = nFileRecv*2;
      if( mxPhantomReq<200 ) mxPhantomReq = 200;
    }
    nCardRcvd = 0;
    xfer.nFileRcvd = 0;
    xfer.nDeltaRcvd = 0;
    xfer.nDanglingFile = 0;

    /* If we have one or more files queued to send, then go
    ** another round 
    */
    if( xfer.nFileSent+xfer.nDeltaSent>0 ){
      go = 1;
    }

    /* If this is a clone, the go at least two rounds */
    if( cloneFlag && nCycle==1 ) go = 1;
  };
  transport_stats(&nSent, &nRcvd, 1);
  printf("Total network traffic: %d bytes sent, %d bytes received\n",
         nSent, nRcvd);
  transport_close();
  transport_global_shutdown();
  db_multi_exec("DROP TABLE onremote");
  manifest_crosslink_end();
  db_end_transaction(0);
}